1. Field of the Invention
The present invention relates to a sewing device suitable for pattern sewing or embroidery sewing.
2. Description of the Related Art
Unexamined Japanese Patent Application (Kokai) No. HEI-6-126054 and U.S. Pat. No. 5,474,001 describe examples of multi-head embroidery machines used as industrial sewing machines for sewing patterns and embroidery.
The multi-head embroidery machine disclosed in Unexamined Japanese Patent Application (Kokai) No. HEI-6-126054 includes a plurality of embroidery machines aligned horizontally (i.e. in an X-direction) at a predetermined interval from each other. A cloth-feeding mechanism is provided for independently driving feeding movement in X and Y directions of a common movable frame on which are attached a plurality of embroidery frames. A needle bar case housing a plurality of needle bars, each corresponding to one of a plurality of colors of embroidery yarn, is provided to a head portion of each embroidery machine. The position of the needle bar case is freely changeable in the vertical direction, as required for the shape of the workpiece cloth. The head portion is configured so that drive force from a main drive shaft, which is driven by a sewing machine motor, is distributed to both a principal shaft and a loop taker shaft of each embroidery machine.
Each of the sewing machines includes a bed portion, a column portion, and an arm portion, which extends vertically from the upper end of the column portion. The head portion is provided to the tip of the arm portion and includes components driven by the principal shaft, such as the needle bars and corresponding sewing needles, and the levers. A loop taker shaft driven by the shuttle shaft is provided to the bed portion. It should be noted that there are two types of bed portion: a bed type capable of sewing only flat pieces of cloth and a cylinder bed type capable of sewing cylindrical pieces of cloth.
U.S. Pat. No. 5,474,001 describes an arm type multi-head type embroidery machine having basically the same configuration as the multi-head type embroidery machine described in Unexamined Japanese Patent Application (Kokai) No. HEI-6-126054. However, this multi-head type embroidery machine is a bridge-type machine wherein the arm portion is dispensed with and also the plurality of head portions and the plurality of the bed portions are integrally fixed to the support frame.
Examined Japanese Patent Application (Kokai) No. SHO-60-21750, Unexamined Japanese Utility Model Application (Kokai) No. SHO-61-15816, and Unexamined Japanese Patent Application (Kokai) No. HEI-3-234291 and describe sewing machines configured so that the loop taker is driven independently from the machine principal shaft by a separate drive motor for loop taker drive. The drive motor for loop taker drive and a transmission system for transmitting the drive force from the drive motor to loop taker drive are fixedly provided to the bed portion.